C++ STL Test - 4 - Sanfoundry

1. Which function is used to check whether a given sequence is heap or not?

sort_heap()

check_heap()

is_heap_until()

is_heap()

2. Which function is used to construct heap from given sequence of numbers?

make_heap()

construct_heap()

start_heap()

create_heap()

3. What is the use of is_heap_until() function?

Returns the iterator of the first element of the sequence

Returns the iterator of the last element of the sequence always

Returns the iterator to the position from where the sequence is a heap

Returns the iterator of the position till that the sequence is a heap

4. Elements in STL heap are removed in ________________________

input order

decreasing order

increasing order

alternate i.e. once max element then min element

5. What is the use of sort_heap() function in heap?

To sort the second half of the heap

To sort the elements in the heap into descending order

To sort the elements in the heap into ascending order

To sort the first half of the heap

6. Which type of heap is implemented in STL heap?

min heap

middle heap

close heap

max heap

7. What will be the output of the following C++ code?

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(int argc, char const *argv[])
{
	vector <int> v = {1,5,23,90,15,35};
	make_heap(v.begin(),v.end());
	v.push_back(110);
	push_heap(v.begin(), v.end());
	pop_heap(v.begin(), v.end());
	v.pop_back();
	cout<<v.front();
}

110

8. What will be the output of the following C++ code?

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(int argc, char const *argv[])
{
	vector <int> v = {1,5,23,90,15,35};
	make_heap(v.begin(),v.end());
	cout<<v.front();
}

9. What will be the output of the following C++ code?

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(int argc, char const *argv[])
{
	vector <int> v = {90, 47, 34, 23, 4, 35, 67};
	auto it = is_heap_until(v.begin(), v.end());
	for(auto i = v.begin(); i != it; i++)
		cout<<*i<<" ";
}

90 67 47 35 34 23 4

90 47 34 23 4 35

90 47 34 23 4

90 47 34 23 4 35 67

10. Which header file is required to use heap in your program?

<map>

<heap>

11. Which function is used to insert an element into heap?

pop_back()

push_heap()

pop_heap()

push_back()

12. What is the use of front() function in heap?

Returns the first element of the heap

Returns the last element of the heap

Returns the element closest to the median of a sequence

Returns the element closest to mean of a sequence

13. Which of the following is correct syntax of making heap from a vector v?

make_heap(v.end(), v.begin());

make_heap(v.elements);

make_heap(v.begin(), v.end());

make_heap(v);

14. What will be the output of the following C++ code?

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(int argc, char const *argv[])
{
	vector <int> v = {1,5,23,90,15,35};
	make_heap(v.begin(),v.end());
	v.push_back(110);
	push_heap(v.begin(), v.end());
	cout<<v.front();
}

110

15. What will be the output of the following C++ code?

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(int argc, char const *argv[])
{
	vector <int> v = {1,5,23,90,15,35};
	cout<<is_heap(v.begin(), v.end());
	make_heap(v.begin(), v.end());
	cout<<is_heap(v.begin(), v.end());
}